2013-01-30 16:08:12

by Stanislaw Gruszka

[permalink] [raw]
Subject: [PATCH -next] iwlegacy: check for dma mapping errors

Handle pci_map_page() errors. This fixes "DMA-API: device driver failed
to check map error" warning.

Reported-by: Zdenek Kabelac <[email protected]>
Signed-off-by: Stanislaw Gruszka <[email protected]>
---
Patch is intended to -next, even if it fix a problem, it is very
unlikely that iwlegacy is used on machine with IOMMU (where
pci_map_page can fail). More probable is using CONFIG_DMA_API_DEBUG,
which generate the warning, but that's is not real problem.

drivers/net/wireless/iwlegacy/3945-mac.c | 39 ++++++++++++++++++--------
drivers/net/wireless/iwlegacy/4965-mac.c | 43 ++++++++++++++++++-----------
2 files changed, 54 insertions(+), 28 deletions(-)

diff --git a/drivers/net/wireless/iwlegacy/3945-mac.c b/drivers/net/wireless/iwlegacy/3945-mac.c
index 050ce7c..83856d1 100644
--- a/drivers/net/wireless/iwlegacy/3945-mac.c
+++ b/drivers/net/wireless/iwlegacy/3945-mac.c
@@ -1001,12 +1001,12 @@ il3945_rx_allocate(struct il_priv *il, gfp_t priority)
struct list_head *element;
struct il_rx_buf *rxb;
struct page *page;
+ dma_addr_t page_dma;
unsigned long flags;
gfp_t gfp_mask = priority;

while (1) {
spin_lock_irqsave(&rxq->lock, flags);
-
if (list_empty(&rxq->rx_used)) {
spin_unlock_irqrestore(&rxq->lock, flags);
return;
@@ -1035,26 +1035,34 @@ il3945_rx_allocate(struct il_priv *il, gfp_t priority)
break;
}

+ /* Get physical address of RB/SKB */
+ page_dma =
+ pci_map_page(il->pci_dev, page, 0,
+ PAGE_SIZE << il->hw_params.rx_page_order,
+ PCI_DMA_FROMDEVICE);
+
+ if (unlikely(pci_dma_mapping_error(il->pci_dev, page_dma))) {
+ __free_pages(page, il->hw_params.rx_page_order);
+ break;
+ }
+
spin_lock_irqsave(&rxq->lock, flags);
+
if (list_empty(&rxq->rx_used)) {
spin_unlock_irqrestore(&rxq->lock, flags);
+ pci_unmap_page(il->pci_dev, page_dma,
+ PAGE_SIZE << il->hw_params.rx_page_order,
+ PCI_DMA_FROMDEVICE);
__free_pages(page, il->hw_params.rx_page_order);
return;
}
+
element = rxq->rx_used.next;
rxb = list_entry(element, struct il_rx_buf, list);
list_del(element);
- spin_unlock_irqrestore(&rxq->lock, flags);

rxb->page = page;
- /* Get physical address of RB/SKB */
- rxb->page_dma =
- pci_map_page(il->pci_dev, page, 0,
- PAGE_SIZE << il->hw_params.rx_page_order,
- PCI_DMA_FROMDEVICE);
-
- spin_lock_irqsave(&rxq->lock, flags);
-
+ rxb->page_dma = page_dma;
list_add_tail(&rxb->list, &rxq->rx_free);
rxq->free_count++;
il->alloc_rxb_page++;
@@ -1284,8 +1292,15 @@ il3945_rx_handle(struct il_priv *il)
pci_map_page(il->pci_dev, rxb->page, 0,
PAGE_SIZE << il->hw_params.
rx_page_order, PCI_DMA_FROMDEVICE);
- list_add_tail(&rxb->list, &rxq->rx_free);
- rxq->free_count++;
+ if (unlikely(pci_dma_mapping_error(il->pci_dev,
+ rxb->page_dma))) {
+ __il_free_pages(il, rxb->page);
+ rxb->page = NULL;
+ list_add_tail(&rxb->list, &rxq->rx_used);
+ } else {
+ list_add_tail(&rxb->list, &rxq->rx_free);
+ rxq->free_count++;
+ }
} else
list_add_tail(&rxb->list, &rxq->rx_used);

diff --git a/drivers/net/wireless/iwlegacy/4965-mac.c b/drivers/net/wireless/iwlegacy/4965-mac.c
index f1dc040..38f14c1 100644
--- a/drivers/net/wireless/iwlegacy/4965-mac.c
+++ b/drivers/net/wireless/iwlegacy/4965-mac.c
@@ -319,6 +319,7 @@ il4965_rx_allocate(struct il_priv *il, gfp_t priority)
struct list_head *element;
struct il_rx_buf *rxb;
struct page *page;
+ dma_addr_t page_dma;
unsigned long flags;
gfp_t gfp_mask = priority;

@@ -356,33 +357,35 @@ il4965_rx_allocate(struct il_priv *il, gfp_t priority)
return;
}

+ /* Get physical address of the RB */
+ page_dma =
+ pci_map_page(il->pci_dev, page, 0,
+ PAGE_SIZE << il->hw_params.rx_page_order,
+ PCI_DMA_FROMDEVICE);
+ if (unlikely(pci_dma_mapping_error(il->pci_dev, page_dma))) {
+ __free_pages(page, il->hw_params.rx_page_order);
+ break;
+ }
+
spin_lock_irqsave(&rxq->lock, flags);

if (list_empty(&rxq->rx_used)) {
spin_unlock_irqrestore(&rxq->lock, flags);
+ pci_unmap_page(il->pci_dev, page_dma,
+ PAGE_SIZE << il->hw_params.rx_page_order,
+ PCI_DMA_FROMDEVICE);
__free_pages(page, il->hw_params.rx_page_order);
return;
}
+
element = rxq->rx_used.next;
rxb = list_entry(element, struct il_rx_buf, list);
list_del(element);

- spin_unlock_irqrestore(&rxq->lock, flags);
-
BUG_ON(rxb->page);
- rxb->page = page;
- /* Get physical address of the RB */
- rxb->page_dma =
- pci_map_page(il->pci_dev, page, 0,
- PAGE_SIZE << il->hw_params.rx_page_order,
- PCI_DMA_FROMDEVICE);
- /* dma address must be no more than 36 bits */
- BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));
- /* and also 256 byte aligned! */
- BUG_ON(rxb->page_dma & DMA_BIT_MASK(8));
-
- spin_lock_irqsave(&rxq->lock, flags);

+ rxb->page = page;
+ rxb->page_dma = page_dma;
list_add_tail(&rxb->list, &rxq->rx_free);
rxq->free_count++;
il->alloc_rxb_page++;
@@ -4281,8 +4284,16 @@ il4965_rx_handle(struct il_priv *il)
pci_map_page(il->pci_dev, rxb->page, 0,
PAGE_SIZE << il->hw_params.
rx_page_order, PCI_DMA_FROMDEVICE);
- list_add_tail(&rxb->list, &rxq->rx_free);
- rxq->free_count++;
+
+ if (unlikely(pci_dma_mapping_error(il->pci_dev,
+ rxb->page_dma))) {
+ __il_free_pages(il, rxb->page);
+ rxb->page = NULL;
+ list_add_tail(&rxb->list, &rxq->rx_used);
+ } else {
+ list_add_tail(&rxb->list, &rxq->rx_free);
+ rxq->free_count++;
+ }
} else
list_add_tail(&rxb->list, &rxq->rx_used);

--
1.7.1